1. Field of the Invention
The present invention relates to a television tuner that receives television broadcast signals with an antenna capable of selecting directivity.
2. Description of the Prior Art
In television broadcasting, transmitter location may differ with each broadcasting station. In such a case, to receive the radio wave from a desired station, it is necessary to set up the receiver to receive the desired channel and also to adjust the directivity of the antenna toward the transmitter of the desired station.
Conventionally, there is known a television tuner that is equipped with a smart antenna capable of statically changing the directivity by means of an electrical signal, and that allows finding a direction in which the desired channel can be best received by automatically and omnidirectionaly changing the directivity of the smart antenna (refer to Japanese Patent Laid-Open No. 11-298226, for example).
Also, the above inventor proposes a television tuner that receives television broadcast signals with the above-mentioned smart antenna, wherein the smart antenna is controlled to change the directivity of the smart antenna omnidirectionaly so as to find a direction in which the desired radio wave is best received, and also to switch receiving channels as appropriate and store receiving channels sequentially which give optimum receiving condition. This television tuner allows automatic storing of receiving channels for all the receiving channels when performing an auto-scan to set receivable television channels, and therefore is very convenient.
However, this television tuner is designed to find the optimum receiving condition by changing the directivity of the smart antenna omnidirectionaly for all the receiving channels, as described above. That is, it is necessary to perform the omnidirectional directivity control of the smart antenna as many times as the number of receiving channels repeatedly. Therefore, it will take too much time if all the channels are scanned. In particular, if the number of receivable channels is large this problem is serious, making the user irritated or uncomfortable.